dmaengine: xilinx_dma : add xilinx_dma_device_config() return documentation

document xilinx_dma_device_config() return value. Fixes below
kernel-doc warning.

xilinx_dma.c:1665: warning: No description found for return value
of 'xilinx_dma_device_config'

Signed-off-by: Radhey Shyam Pandey <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: Radhey Shyam Pandey

drivers/dma/xilinx/xilinx_dma.c

@@ -1659,6 +1659,8 @@ static void xilinx_dma_issue_pending(struct dma_chan *dchan)
  * xilinx_dma_device_config - Configure the DMA channel
  * @dchan: DMA channel
  * @config: channel configuration
+ *
+ * Return: 0 always.
  */
 static int xilinx_dma_device_config(struct dma_chan *dchan,
 				    struct dma_slave_config *config)